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Image brush strokes

Image brush strokes act the same as vector brush strokes (they are stretched and fit along any destination path), but they are defined from bitmapped images. However, the method for making an image stroke is different than for vector brush strokes.

1. Insert a bitmapped image in a document. (For details, see Importing bitmapped images.)
2. Select the image object with the Selection tool, and then click Stroke on the Object menu, and then click Define Image Stroke. This opens the Define Image Stroke dialog box.

3. Type a new stroke name in the Stroke Name field and select a stroke category from the Folder drop-down list.
4. Type the default width in the Default Width field. This is the value used when you select a path that is currently set to no stroke, and then click this stroke in the Stroke/Brush List panel.
5. The Alpha Channel section lets you control the image stroke's transparency and color.
   • Select No Alpha if you do not want to include image transparency, and you do not want the  Properties panel to override the image color.
   • Select Use the Original Alpha if you want the image stroke to contain transparent areas.
   • Select Grayscale to convert the image to grayscale so that it can easily be colorized with the Properties panel. Grayscale image strokes are inherently partially transparent (lighter areas are more transparent).
6. If you do not want repeating sections in the image stroke, click OK. Otherwise, see "Anchored and repeating body sections," below.

Examples of bitmapped images (left column) and image strokes based on them (right column)

Anchored and repeating body sections

The two ends of an image stroke can be anchored, and the middle section can be made into one or more repeatable parts. By anchoring each end of an image stroke, you can ensure that it is not stretched to fit the destination path. To anchor one or both ends of the stroke, type the length in pixels to be anchored in either the Anchor Head Section Length field or the Anchor Tail Section Length field of the New Image Stroke dialog box or the Edit Image Stroke dialog box. (For more on how to edit already-existing strokes, see Editing strokes.)

If you do not specify a repeating section, then the two ends (up to the number of pixels you specified) will remain unstretched and the middle section will stretch to fit the path (assuming the final path is longer than the image stroke is wide). However, image strokes can be defined to contain one or more repeatable body sections of equal length. To specify one or more repeating sections, choose from the Body Section drop-down list of the  Define Image Stroke dialog box or the Edit Image Stroke dialog box.

• When you choose Simple Repeat, the entire middle section (defined as any part of the image that isn't taken by the anchored head or tail) is repeated as many times as will fit along the path.
• If you choose 2-part Repeat, the middle section is split evenly in two and the two parts randomly alternate along the path.
• If you choose a repeat of three or more parts, the parts appear in random order along the path, and there will be a different combination for each new path to which you apply this stroke.

Here, a bitmapped image (1) has been converted into three image strokes. The first stroke (2) has a 50-point anchored head and tail, but no repeating middle. The second (3) has a one-part repeating middle. The third stroke (4) has a two-part randomly repeating middle, so it looks less regular.